In order to reduce the emissions of nitrogen monoxide and nitrogen dioxide into the exhaust gases, ammonia is generally injected into the exhaust gas system. The ammonia then reacts with the nitrogen monoxide and nitrogen dioxide, producing nitrogen and water.
For safety reasons, the ammonia is not stored in crude form, but in the form of a material, generally made by ammonia absorption or adsorption by metal chloride salts. This material thus obtained is then stored in said cartridge.
During use, the cartridge is heated such that the ammonia stored therein is desorbed, in order to be injected in gas form into the exhaust gas system.
Thus, an ammonia storage cartridge is already known in the state of the art, in particular for a motor vehicle gas exhaust system, including an ammonia storage member comprising a material capable of absorbing or adsorbing ammonia, the storage member extending along a longitudinal axis.
After the ammonia contained in the cartridge has been desorbed, it is necessary to recharge the cartridge by filling it with ammonia again. To that end, the cartridge is generally equipped with an input and output nozzle for the ammonia in fluid form, i.e., liquid or gas, said nozzle being arranged at a first end of the cartridge in the direction of the longitudinal axis.
The method for filling the cartridge is generally particularly time-consuming to implement. Indeed, the metal chloride salts together forming a particularly dense material, the diffusion of the ammonia in that material is difficult, in particular to reach a second end of the cartridge opposite the first end equipped with the nozzle.